This spell animates a tree's branch and directs it against your foes. At caster level 10th or lower, you can target a Huge tree. At caster level 11th–15th, you can target a Gargantuan tree, and at caster level 16th or higher you can target a Colossal tree. The animated branch makes slam attacks with a Strength score equal to 10 + your caster level. The branch strikes once per round with an attack bonus equal to your caster level + the branch's Strength modifier, adjusted by the appropriate size modifier (–2 for Huge, –4 for Gargantuan, –8 for Colossal). A Huge tree's slam deals 2d6 points of damage, a Gargantuan tree's slam deals 3d6 points of damage, and a Colossal tree's slam deals 4d6 points of damage; the tree adds 1-1/2 times its Strength modifier to this damage. A Huge tree has reach 15 feet, a Gargantuan has reach 20 feet, and a Colossal has reach 30 feet. The tree attacks the creature you designate when you cast the spell, and is unable to move. You can direct the tree against a new target as a move action. The tree does not gain a bonus for flanking, nor can it help another combatant flank. It cannot attack a foe you cannot see.